1. Field
One embodiment of the invention relates to a video decoding apparatus and a video decoding method which decodes a video stream which has been compressed and encoded.
2. Description of the Related Art
As standard technologies for encoding a video stream, H.261 and H.263 of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T), Moving Picture Experts Group (MPEG)-1, MPEG-2, and MPEG-4 of the International Organization for Standardization (ISO), and the like, have been developed. As a next-generation video encoding method in which the technologies such as H.261 to H.263, MPEG-1 to MPEG-4, and the like have been succeeded, and further developed, there is the H.264 which has been standardized by the ISO and the ITU jointly (refer to ITU-T Recommendation H.264 (2003), “Advanced Video Coding for generic audiovisual services” | ISO/IEC 14496-10: 2003, “Information technology, Coding of audio-visual objects—Part 10: Advanced video coding”, and H.264/AVC textbook (Impress Communications Corporation)).
However, the H.264 accomplishes high compressibility and yet produces a problem that its processing amount is large. In particular, reproducing a video with high compressibility from a medium, such as an HD-DVD, requires a high arithmetic processing capability, so that it causes serious problems. Specifically, in a video decoding apparatus with such standardization specifications based on the H.264, compensating movements of inter predictions accounting to the whole of decoding processing being large in quantity, there is a possibility that such a disadvantage occurs that decoding processing in real time cannot be made in time, frames are missed, and movements of objects are extremely become slow, if the load on the whole of the decoding apparatus is heavy.